As filed with the Securities and Exchange Commission on January 9, 2001

                        Registration No. 333-49804

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                AMENDMENT NO. 1
                                       TO
                                    FORM S-3

                             Registration Statement
                        Under The Securities Act of 1933

                      TRANSACTION SYSTEMS ARCHITECTS, INC.
             (Exact name of registrant as specified in its charter)


                               Delaware 47-0772104
        (State or other jurisdiction (I.R.S. Employer Identification No.)
                        of incorporation or organization)

                             224 South 108th Avenue
                              Omaha, Nebraska 68154
                                 (402) 334-5101
   (Address, including ZIP Code, and telephone number, including area code, of
                    registrant's principal executive offices)

                         ------------------------------
                 David P. Stokes, General Counsel and Secretary
                      Transaction Systems Architects, Inc.
                             224 South 108th Avenue
                              Omaha, Nebraska 68154
                                 (402) 334-5101
 (Name, address, including Zip Code, and telephone number, including area code,
                              of agent for service)

                                    Copy to:
                                 Alan G. Harvey
                                Baker & McKenzie
                            2300 Trammell Crow Center
                                2001 Ross Avenue
                               Dallas, Texas 75201
                                 (214) 978-3000
                      ------------------------------------
 Approximate date of commencement of proposed sale to the public: From time to
         time after the effective date of this registration statement.

     If the only securities being registered on this Form are being offered
     pursuant to dividend or interest reinvestment plans, please check the
                               following box. [ ]

 If any of the securities being registered on this Form are to be offered on a
  delayed or continuous basis pursuant to Rule 415 under the Securities Act of
    1933, other than securities offered only in connection with dividend or
           interest reinvestment plans, check the following box. [X]

    If this Form is filed to register additional securities for an offering
  pursuant to Rule 462(b) under the Securities Act, please check the following
  box and list the Securities Act registration statement number of the earlier
          effective registration statement for the same offering. [ ]

 If this Form is a post-effective amendment filed pursuant to Rule 462(c) under
    the Securities Act, check the following box and list the Securities Act
 registration statement number of the earlier effective registration statement
                           for the same offering. [ ]

   If delivery of the prospectus is expected to be made pursuant to Rule 434,
                      please check the following box. [ ]

                      ------------------------------------

         THE REGISTRANT HEREBY AMENDS THIS  REGISTRATION  STATEMENT ON SUCH DATE
OR DATES AS MAY BE NECESSARY TO DELAY ITS  EFFECTIVE  DATE UNTIL THE  REGISTRANT
SHALL  FILE  A  FURTHER   AMENDMENT   WHICH   SPECIFICALLY   STATES   THAT  THIS
REGISTRATION  STATEMENT  SHALL  THEREAFTER  BECOME  EFFECTIVE IN ACCORDANCE WITH
SECTION 8(a) OF THE SECURITIES ACT OF 1933 OR UNTIL THE  REGISTRATION  STATEMENT
SHALL BECOME  EFFECTIVE ON SUCH DATE AS THE COMMISSION,  ACTING PURSUANT TO SAID
SECTION 8(a), MAY DETERMINE.





The  information in this  prospectus is not complete and may be changed.  We may
not sell  these  securities  until the  registration  statement  filed  with the
Securities  and Exchange  Commission  is  effective.  This  Prospectus is not an
offer to sell these  securities  and it is not  soliciting an offer to buy these
securities in any state where the offer or sale is not permitted.

                  Subject to completion, dated January 9, 2001

Prospectus

                                3,157,500 Shares
                      Transaction Systems Architects, Inc.
                              Class A Common Stock

                      ------------------------------------

         The shares  of TSA Class A Common Stock covered  by this prospectus are
issuable upon exchange or  redemption  of TSA  Exchangeco  Limited  exchangeable
shares.  TSA Exchangeco is a  wholly-owned  subsidiary  of TSA.  TSA  Exchangeco
issued the  exchangeable shares  in  exchange for  MessagingDirect  Ltd. Class A
common shares in connection with the acquisition of MessagingDirect by TSA.

         This  prospectus  is part of a  registration  statement  that we  filed
with the SEC using a shelf  registration  process.  This  means we may issue the
TSA Class A Common Stock covered by this  prospectus  from time to time when the
holders of TSA  Exchangeco  exchangeable  shares  present their  securities  for
exchange.  Upon exchange,  holders of exchangeable  shares will receive for each
exchangeable share one share of TSA Class A Common Stock.

         TSA  Class A Common  Stock is  listed  on the  Nasdaq  National  Market
under the symbol  "TSAI."  The  closing  market  price of the TSA Class A Common
Stock on  January 8, 2001  was  $11.9375  per  share.  The  principal  executive
offices of TSA are located at 224 South 108th  Avenue,  Omaha,  Nebraska  68154,
and its telephone number is (402) 334-5101.

                      ------------------------------------

                               Consider carefully
                      the risk factors beginning on page 3.

                      ------------------------------------

    Neither the Securities and Exchange Commission nor any state securities
 commission has approved or disapproved of these securities or passed upon the
  adequacy or accuracy of this prospectus. Any representation to the contrary
                             is a criminal offense.

                      ------------------------------------

                The date of this prospectus is ________ __, 2001.


         You should rely only on the  information  provided  in this  prospectus
or  incorporated  into  it by  reference.  No  person  has  been  authorized  to
provide  you with  different  information.  Transaction  Systems  Architects  is
not  making an offer of these  securities  in any  state  where the offer is not
permitted.  Information  is  accurate  only  as of the  date  of  the  documents
containing the information,  unless the information  specifically indicates that
another date applies.

                      ------------------------------------

                                TABLE OF CONTENTS

                                                                            PAGE

RISK FACTORS...........................................................        3

THE COMPANY............................................................        3

WHERE YOU CAN FIND MORE INFORMATION; INCORPORATION BY REFERENCE........        3

FORWARD-LOOKING STATEMENTS.............................................        4

USE OF PROCEEDS........................................................        5

DESCRIPTION OF TSA CAPITAL STOCK.......................................        5

PLAN OF DISTRIBUTION...................................................        7

INCOME TAX CONSIDERATIONS..............................................       10

LEGAL MATTERS..........................................................       16

EXPERTS................................................................       16



                                  RISK FACTORS

     In addition to the other  information in this  prospectus  and  information
incorporated by reference,  you should carefully consider the following factors,
in evaluating your decision to exchange TSA Exchangeco  exchangeable  shares for
shares of TSA common stock.

Exchange of exchangeable shares is taxable

         The exchange of TSA  Exchangeco  exchangeable  shares for shares of TSA
common  stock is generally a taxable  event under  current law in Canada and, in
certain  circumstances,  the United States.  See "Income Tax  Considerations." A
holder's tax consequences  can vary depending on a number of factors,  including
the  residency  of the  holder  and the method of the  exchange  (retraction  or
redemption by TSA Exchangeco or purchase by TSA or TSA Holdco).

Exchangeable shares are not qualified investments for some plans and funds

         The  TSA   Exchangeco   exchangeable   shares  will  not  be  qualified
investments   for  trusts  governed  by  Canadian   retirement   savings  plans,
registered  retirement  income  funds and deferred  profit  sharing  plans.  The
acquisition  of TSA  Exchangeco  exchangeable  shares  by these  plans and funds
will  result in an income  inclusion  to the  annuitant  under  these  plans and
funds  equal  to the  fair  market  value  of the  TSA  Exchangeco  exchangeable
shares,  and these  plans and funds  will also be taxed on the  income and gains
from the TSA Exchangeco exchangeable shares under the Income Tax Act (Canada).

Exchangeable  shares  and  TSA  common  stock  are  foreign  property  for  some
tax-exempt holders

         The TSA  Exchangeco  exchangeable  shares and the TSA common stock will
be foreign  property for trusts governed by Canadian  retirement  savings plans,
registered  retirement income funds,  deferred profit sharing plans,  registered
pension  plans and for some other  tax-exempt  persons.  These plans,  funds and
tax-exempt   persons  have  to  limit  their   investment   in  TSA   Exchangeco
exchangeable  shares and TSA common stock or risk incurring  penalties under the
Income  Tax Act  (Canada).  The Canada  Customs  and  Revenue  Agency has stated
that the  penalties  will not be levied  where the  exchangeable  shares are not
qualified  investments  for  trusts  governed  by  Canadian  retirement  savings
plans,  registered  retirement  income funds and deferred  profit  sharing plans
and subject to the tax described in the preceding paragraph.

                                   THE COMPANY

         TSA develops,  markets,  installs and supports a broad line of software
products and services  primarily  focused on  facilitating  electronic  payments
and  electronic   commerce.   TSA's  software   products  are  used  to  process
transactions  involving  automated  teller machines (ATM),  point-of-sale  (POS)
terminals,  credit  cards,  debit cards,  smart  cards,  checks,  manned  teller
devices,  remote  banking,  wire  transfers and automated  clearing  house (ACH)
functions.  TSA's  products and services  assist  customers in operating  large,
complex  networks  performing  such  functions  as  transaction   authorization,
transaction routing,  debit and credit card management,  transaction  settlement
and reporting.

         Additional  information  concerning TSA is included in TSA's  documents
filed with the SEC,  which are  incorporated  by reference  into this  document.
See "Where You Can Find More Information; Incorporation by Reference."

         WHERE YOU CAN FIND MORE INFORMATION; INCORPORATION BY REFERENCE

         We file annual,  quarterly and special  reports,  proxy  statements and
other  information  with the  Securities and Exchange  Commission.  You may read
and copy (upon the payment of fees  prescribed  by the SEC) any document that we
file with the SEC at its public  reference rooms in Washington,  D.C. (450 Fifth
Street,  N.W.  20549),  New York,  New York (7 World  Trade  Center,  Suite 1300
10048),  and  Chicago,  Illinois  (500 West Madison  Street,  Suite 1400 60661).
You may call the SEC at  1-800-SEC-0330  for further  information  on the public
reference   rooms.  Our  filings  are  also  available  to  the  public  on  the
internet,  through the SEC's EDGAR  database.  You may access the EDGAR database
at the SEC's web site at http://www.sec.gov.

         The SEC allows us to  "incorporate  by reference"  into this prospectus
the  information  we file with it.  This  means that we can  disclose  important
business,  financial  and other  information  in our filings by referring you to
the documents  containing  this  information.  All  information  incorporated by
reference  is part of this  prospectus,  unless  and until that  information  is
updated and superseded by the  information  contained in this  prospectus or any
information  incorporated  later.  Any  information  that we  subsequently  file
with the SEC that is  incorporated  by reference will  automatically  update and
supersede  any  previous  information  that  is  part  of  this  prospectus.  We
incorporate  into this  prospectus by reference the following  documents and any
subsequent  filings we make with the SEC under  Sections  13(a),  13(c),  14, or
15(d) of the Securities Exchange Act of 1934:

o        Annual  Report on Form 10-K for the  fiscal  year ended  September  30,
          2000; and
o        The   description  of  our  Class  A  Common  Stock  contained  in  our
          registration  statement  on Form  8-A  that we  filed  with the SEC on
          January 11, 1995 under the  Securities  Exchange  Act,  including  any
          amendment or reports  that we file for the  purposes of updating  this
          description.

This  prospectus  is part of a  registration  statement on Form S-3 that we have
filed with the SEC  relating to the shares of  Transaction  Systems  Architect's
Class A Common  Stock  offered by this  prospectus.  As  permitted by SEC rules,
this  prospectus  does  not  contain  all  the  information  contained  in  that
registration  statement and its  accompanying  exhibits and  schedules  which we
have  also  filed  with the SEC.  You may refer to the  registration  statement,
the exhibits and schedules  for more  information  about us and our shares.  The
registration  statement,  exhibits  and  schedules  are  available  at the SEC's
public reference rooms or through its EDGAR database on the internet.

         You may  obtain a copy of these  filings,  at no cost,  by  writing  or
telephoning us at the following address:

                  David P. Stokes
                  General Counsel and Secretary
                  Transaction Systems Architects, Inc.
                  224 South 108th Avenue
                  Omaha, Nebraska 68154
                  (402) 334-5101

         To ensure  timely  delivery  of these  materials,  you should  make any
request  no later  than five  business  days prior to the date on which you must
make your investment decision.

                           FORWARD-LOOKING STATEMENTS

         This  prospectus  and the  documents we  incorporate  by reference  may
contain   "forward-looking   statements"  within  the  meaning  of  the  Private
Securities  Litigation  Reform Act of 1995,  all of which are  subject to risks,
uncertainties  and  assumptions.  We wish to  ensure  that such  statements  are
accompanied  by  meaningful  cautionary  statements,  so as  to  ensure  to  the
fullest extent  possible the  protections of the safe harbor  established in the
Private  Securities  Litigation Reform Act.  Statements other than statements of
existing or  historical  fact we make in this  prospectus  or the  documents  we
incorporate  by  reference  are  forward-looking.  Words such as  "anticipates,"
"expects,"  "intends," "plans," "believes,"  "seeks,"  "estimates," "forecasts,"
"projects,"  and  similar  expressions  identify   forward-looking   statements.
However,  the  absence  of  these  words  does  not  mean  a  statement  is  not
forward-looking.   Actual   results   may  differ   materially   from  those  in
forward-looking  statements  due to many  factors,  including  those  set  forth
above  in "Risk  Factors"  or in  documents  we  incorporate  by  reference.  We
operate  in a  rapidly  changing  and  evolving  business  involving  electronic
commerce  and  payments,  and new risk  factors  will likely  emerge.  We cannot
predict or identify all important risk factors.

                                 USE OF PROCEEDS

         Because  the shares of TSA common  stock will be issued on  exchange or
redemption of the TSA Exchangeco  exchangeable  shares, TSA will receive no cash
proceeds on that issuance.

                        DESCRIPTION OF TSA CAPITAL STOCK

         TSA's Amended and Restated  Certificate of Incorporation  provides that
TSA's authorized  capital stock consists of 50,000,000  shares of Class A Common
Stock,  par value $0.005 per share,  5,000,000  shares of Class B Common  Stock,
par value  $0.005  per share,  and  5,450,000  shares of  preferred  stock,  par
value of $0.01 per share.

Common Stock

         The  Class A  Common  Stock  and  Class B  Common  Stock  have the same
rights  except  that  holders of Class B Common  Stock are not  entitled to vote
except as  provided  by law.  Holders of Class A Common  Stock are  entitled  to
one vote per share on all  matters to be voted on by the  stockholders.  Subject
to  preferences  that may be applicable to any preferred  stock  outstanding  at
the time,  holders  of  Common  Stock  are  entitled  to  receive  ratably  such
dividends,  if any,  as may be  declared  from  time to  time  by the  Board  of
Directors  out of  funds  legally  available.  In the  event  of a  liquidation,
dissolution  or winding up of TSA,  holders of all Common  Stock are entitled to
share ratably in all assets  remaining  after payment of TSA's  liabilities  and
the  liquidation  preference,  if  any,  of  any  outstanding  preferred  stock.
Holders  of Common  Stock  have no  preemptive  rights  and no rights to convert
their  Class A  Common  Stock  into  any  other  securities,  and  there  are no
redemption  provisions  with  respect  to  shares of  Common  Stock.  All of the
outstanding  shares of  Common  Stock are  fully  paid and  non-assessable.  The
rights,  preferences  and  privileges of holders of Common Stock are subject to,
and may be  adversely  affected  by, the rights of the  holders of shares of any
series of preferred stock which TSA may designate and issue.

Preferred Stock

         The Board of Directors has the  authority,  without any further vote or
action by the  stockholders,  to provide  for the  issuance  of up to  5,450,000
shares of  preferred  stock  from time to time in one or more  series  with such
designations,  rights,  preferences  and  limitations  as the Board of Directors
may determine,  including the  consideration  received  therefor,  the number of
shares   comprising  each  series,   dividend  rates,   redemption   provisions,
liquidation preferences,  sinking fund provisions,  conversion rights and voting
rights,  all without  approval by the  holders of Common  Stock.  Although it is
not  possible to state the effect that any  issuance  of  preferred  stock might
have on the rights of holders of Common Stock,  the issuance of preferred  stock
may have one or more of the following effects:

         (1)      restrict  Common Stock  dividends if preferred stock dividends
have not been paid,

         (2)      dilute the  voting  power and  equity  interest  of holders of
Common Stock, or

         (3)      prevent  current  holders of Common  Stock from  participating
                  in  TSA's  assets  upon  liquidation   until  any  liquidation
                  preferences   granted  to  holders  of  preferred   stock  are
                  satisfied.
In addition,  the issuance of preferred stock may, under certain  circumstances,
have the effect of  discouraging  a change in  control  of TSA by, for  example,
granting  voting rights to holders of preferred  stock that require  approval by
the separate  vote of the holders of preferred  stock for any amendment to TSA's
Amended  and  Restated  Certificate  of  Incorporation  or  any  reorganization,
consolidation,  merger  (or  other  similar  transaction  involving  TSA).  As a
result,  the issuance of such preferred  stock may discourage bids for the TSA's
Common  Stock at a premium  over the  market  price  therefor  and could  have a
material  adverse  effect on the market  value of the Common  Stock.  Except for
the one share of Special  Preferred  Voting Stock described  below, no shares of
preferred stock are currently outstanding.

Special Preferred Voting Stock

         The TSA  Board of  Directors  has  designated  one  share of  Preferred
Stock as Special  Preferred  Voting Stock.  The Special  Preferred  Voting Stock
was issued  in connection  with  the  acquisition  of MessagingDirect by TSA. On
all matters  presented to holders of TSA commons  stock,  the Special  Preferred
Voting  Stock is  entitled  to the  number  of  votes  equal  to the  number  of
outstanding  TSA  Exchangeco  exchangeable  shares  not  held  by  TSA  and  its
affiliates.  The  Special  Preferred  Voting  Stock is held by a trustee for and
on behalf of the holders of TSA  Exchangeco  exchangeable  shares.  For each TSA
Exchangeco  exchangeable  share held on the record date,  the holder is entitled
to  instruct  the  trustee  as to the  manner of voting  one vote.  The  Special
Preferred  Voting  Stock and the TSA  common  stock  vote  together  as a single
class.  No  dividend  will be paid to the  holder of  Special  Preferred  Voting
Stock.  The Special  Preferred  Voting Stock is not  convertible.  The holder of
the  Special  Preferred  Voting  Stock is not  entitled  to  participate  in any
payment  or  distribution  upon any  liquidation,  dissolution  or winding up of
TSA.  Any  share of  Special  Preferred  Voting  Stock  purchased  or  otherwise
acquired  by TSA  will  be  canceled  and  may  not be  reissued.  When  the TSA
Exchangeco   exchangeable  shares  are  no  longer   outstanding,   the  Special
Preferred Voting Stock will automatically be cancelled.

Limitation of Liability

         TSA's  Amended and Restated  Certificate  of  Incorporation  limits the
liability  of  directors  to the  maximum  extent  permitted  by  Delaware  law.
Delaware law provides  that  directors of a  corporation  will not be personally
liable for monetary  damages for breach of their fiduciary  duties as directors,
including gross  negligence,  except  liability for (1) breach of the directors'
duty of  loyalty,  (2) acts or  omissions  not in good  faith  or which  involve
intentional  misconduct  or a knowing  violation  of the law,  (3) the  unlawful
payment of a dividend  or unlawful  stock  purchase  or  redemption  and (4) any
transaction  from which the  director  derives  an  improper  personal  benefit.
Delaware law does not permit a  corporation  to  eliminate a director's  duty of
care,   and  this   provision  of  TSA's   revised   Restated   Certificate   of
Incorporation has no effect on the availability of equitable  remedies,  such as
injunction or rescission, based upon a director's breach of the duty of care.

         TSA's  Amended and Restated  Certificate  of  Incorporation  authorizes
TSA to purchase and maintain insurance for the purpose of indemnification.

Delaware Law

         Under  Section 203 of the Delaware  General  Corporation  Law,  certain
"business  combinations" between a Delaware corporation whose stock generally is
publicly  traded  or held of  record  by more  than  2,000  stockholders  and an
"interested  stockholder"  are prohibited for a three-year  period following the
date that such stockholder became an interested stockholder, unless:

         (1)      the  corporation  has elected in its original  certificate  of
                  incorporation  not to be  governed by Section 203 (TSA did not
                  make such an election),

         (2)      the  business   combination  was  approved  by  the  board  of
                  directors  of the  corporation  before the other  party to the
                  business combination became an interested stockholder,

         (3)      upon   consummation  of  the  transaction   that  made  it  an
                  interested  stockholder,  the interested  stockholder owned at
                  least 85% of the voting stock of the  corporation  outstanding
                  at the  commencement  of  the  transaction  (excluding  voting
                  stock  owned by  directors  who are also  officers  or held in
                  employee  benefit  plans in which the  employees do not have a
                  confidential  right  to  tender  or  vote  stock  held  by the
                  plan), or

         (4)      the  business   combination  was  approved  by  the  board  of
                  directors of the  corporation  and ratified by  two-thirds  of
                  the voting  stock  which the  interested  stockholder  did not
                  own.

The   three-year   prohibition   also  does  not  apply  to   certain   business
combinations  proposed by an interested  stockholder  following the announcement
or   notification   of  certain   extraordinary   transactions   involving   the
corporation and a person who had not been an interested  stockholder  during the
previous three years or who became an interested  stockholder  with the approval
of  the   majority  of  the   corporation's   directors.   The  term   "business
combination" is defined generally to include mergers or  consolidations  between
a Delaware  corporation and an "interested  stockholder,"  transactions  with an
"interested  stockholder"  involving the assets or stock of the  corporation  or
its  majority-owned  subsidiaries and transactions  which increase an interested
stockholder's    percentage   ownership   of   stock.   The   term   "interested
stockholder"  is  defined   generally  as  a  stockholder  who,   together  with
affiliates and associates,  owns (or, within three years prior,  did own) 15% or
more of a Delaware  corporation's  voting stock.  Section 203 could  prohibit or
delay a merger,  takeover or other change in control of TSA and therefore  could
discourage attempts to acquire the TSA.

Transfer Agent and Registrar

         The  transfer  agent  and  registrar  of the  Class A  Common  Stock is
Wells Fargo Bank Minnesota, N.A.


                              PLAN OF DISTRIBUTION

         Under the terms of a plan of  arrangement  and in  connection  with the
acquisition  of   MessagingDirect   by  TSA,  TSA  Exchangeco   issued  the  TSA
Exchangeco  exchangeable  shares in exchange for  MessagingDirect  Ltd.  Class A
common  shares.  Each  holder of  MessagingDirect  Class A common  shares who is
not a resident of the United  States  could  elect to receive  the  exchangeable
shares or TSA common  stock.  Holders of  MessagingDirect  Class A Common shares
resident  in the  United  States  received  TSA  common  stock.  MessagingDirect
Class A common  shareholders  who properly  exercised  their dissent rights were
not  issued  any  shares  and have  been or will be paid  fair  value  for their
MessagingDirect  Class A common  shares.  TSA  common  stock  may be  issued  to
holders of TSA Exchangeco  exchangeable  shares  through the holder's  election,
TSA Exchangeco's redemption, or TSA Exchangeco's or TSA's liquidation.

Election Of Holders To Retract Exchangeable Shares

         Holders  of TSA  Exchangeco  exchangeable  shares may elect at any time
to have any or all TSA  Exchangeco  exchangeable  shares owned by them exchanged
for an equal number of shares of TSA common  stock,  plus an  additional  amount
equivalent  to  all  declared  and  unpaid  dividends  on  such  TSA  Exchangeco
exchangeable  shares.  The holder's  exercise of this election right is called a
retraction.  Holders of the TSA  Exchangeco  exchangeable  shares may retract by
presenting   to  TSA   Exchangeco  or  its  transfer   agent  the   certificates
representing  the  number  of TSA  Exchangeco  exchangeable  shares  the  holder
desires to retract,  together with a signed notice of retraction  specifying the
number of TSA  Exchangeco  exchangeable  shares the holder wishes to retract and
the date the holder  desires to receive the TSA common  stock.  This  retraction
date  must be  between  ten and  fifteen  business  days  after  TSA  Exchangeco
receives the notice of  retraction.  The  transfer  agent may require the holder
to  submit   additional   documents  to  complete  the  retraction  of  the  TSA
Exchangeco exchangeable shares.

         Upon receipt of the TSA Exchangeco  exchangeable  shares  certificates,
the notice of retraction and other required  documentation  from the holder, TSA
Exchangeco  must  immediately  notify TSA of such retraction  request.  TSA will
then have five  business  days to decide to exercise its  retraction  call right
to purchase  all of the TSA  Exchangeco  exchangeable  shares  submitted  by the
holder.  If TSA does not advise TSA  Exchangeco  within  the five  business  day
period of its decision to exercise this  retraction  call right,  TSA Exchangeco
will  notify  the  holder  as soon as  possible  thereafter  that  TSA  will not
exercise  this  right.  A holder may revoke his or her notice of  retraction  at
any  time  before  the  close  of  business  on  the  business  day  before  the
retraction   date.  If  the  holder  does  not  revoke  his  or  her  notice  of
retraction,  on the  retraction  date either TSA will acquire the TSA Exchangeco
exchangeable  shares  that the holder has  requested  TSA  Exchangeco  to redeem
(assuming  TSA  exercises  its  retraction  call right) or TSA  Exchangeco  will
redeem  those  shares.  In each case the holder  will  receive  one share of TSA
common  stock for each TSA  Exchangeco  exchangeable  share  retracted,  plus an
additional  amount  equivalent to all declared and unpaid  dividends on such TSA
Exchangeco  exchangeable  shares. TSA or TSA Exchangeco,  as the case may be, is
entitled  to sell some of the TSA  common  stock  otherwise  deliverable  to the
holder to fund any withholding tax obligation.

Redemption Of TSA Exchangeco Exchangeable Shares

         Subject  to the  redemption  call  right of TSA  described  below,  TSA
Exchangeco must redeem all of the then  outstanding TSA Exchangeco  exchangeable
shares in exchange  for an equal number of shares of TSA common  stock,  plus an
additional  amount  equivalent to all declared and unpaid  dividends on such TSA
Exchangeco  exchangeable  shares on the redemption  date.  The  redemption  date
will  be (1)  the  fifth  anniversary  of the  closing  of  the  acquisition  of
MessagingDirect  by TSA or (2) an earlier date set by the TSA  Exchangeco  board
of directors if any of the following occurs:

         -        less  than  one-third  of  the  TSA  Exchangeco   exchangeable
                  shares   issued   to    MessagingDirect    shareholders    are
                  outstanding;

         -        a change of  control  of TSA and the TSA  Exchangeco  board of
                  directors  determines  that it is not  reasonably  practicable
                  to  replicate  the  terms  of  the   exchangeable   shares  in
                  connection  with the  change of control  transaction  and that
                  the redemption of all of the outstanding  exchangeable  shares
                  is  necessary  to  enable  the  completion  of the  change  of
                  control transaction in accordance with its terms;

         -        the  proposal  of an event in respect of which  holders of TSA
                  Exchangeco  exchangeable  shares are  entitled  to vote (other
                  than a  change  in  the  rights  of  holders  of  exchangeable
                  shares where  approval of the holders of  exchangeable  shares
                  would   be   necessary   to   maintain   equivalence   of  the
                  exchangeable shares and TSA common stock);

         -        the  proposal  of  a  change  in  the  rights  of  holders  of
                  exchangeable   shares   where   approval  of  the  holders  of
                  exchangeable   shares   would   be   necessary   to   maintain
                  equivalence of the  exchangeable  shares and TSA common stock,
                  and the  holders of the  exchangeable  shares  (other than TSA
                  and its  affiliates)  fail to take  the  necessary  action  to
                  approve or disapprove the proposal; or

         -        the TSA board of directors  resolves to  distribute  shares of
                  any TSA affiliate,  other than TSA  Exchangeco,  to holders of
                  TSA  common  stock or the TSA  board of  directors  determines
                  that  failure to redeem the  exchangeable  shares may create a
                  risk of  adversely  impacting  the  U.S.  federal  income  tax
                  treatment of such a distribution.

         TSA has a  redemption  call right to  purchase on the  redemption  date
all of the  outstanding  TSA  Exchangeco  exchangeable  shares  for a per  share
purchase  price  equal  to one  share of TSA  common  stock  plus an  additional
amount  equivalent  to all declared and unpaid  dividends on the TSA  Exchangeco
exchangeable  share.  TSA Exchangeco will provide the registered  holders of TSA
Exchangeco  exchangeable  shares with written notice of its proposed  redemption
or  TSA's  purchase  of  the  TSA  Exchangeco  exchangeable  shares.  TSA or TSA
Exchangeco,  as the  case  may be,  is  entitled  to  liquidate  some of the TSA
common stock  otherwise  deliverable to the holder to fund any  withholding  tax
obligation.

Liquidation of TSA Exchangeco

         If TSA  Exchangeco  liquidates,  dissolves  or  winds  up its  affairs,
holders of the TSA Exchangeco  exchangeable  shares have preferential  rights to
receive  one  share of TSA  common  stock for each TSA  Exchangeco  exchangeable
share they hold,  plus an  additional  amount  equivalent  to all  declared  and
unpaid  dividends on the holder's TSA  Exchangeco  exchangeable  shares.  If TSA
Exchangeco proposes to liquidate,  dissolve or wind up its affairs,  TSA has the
liquidation  call  right  to  purchase  all of the  outstanding  TSA  Exchangeco
exchangeable  shares from the holders  thereof on the last business day prior to
the  effective  time  of  any  such  event.  TSA,  as  the  owner  of all of the
outstanding  voting  shares  of  TSA  Exchangeco,  has  agreed  not to  vote  to
initiate  the  voluntary   liquidation,   dissolution   or  winding  up  of  TSA
Exchangeco  or to take any  action or omit to take any action  that is  designed
to result in the  liquidation,  dissolution  or  winding  up of TSA  Exchangeco,
other  than a  reorganization  of TSA  Exchangeco  which  results  in TSA or its
affiliates assuming the rights and obligations of TSA Exchangeco.

         On  or  promptly  after  the  effective  time  of  any  TSA  Exchangeco
liquidation,   dissolution   or  winding  up,  holders  of  the  TSA  Exchangeco
exchangeable  shares  must  surrender  their  certificates   representing  those
shares,  together with any other  documents  required by the transfer  agent, to
TSA  Exchangeco's  registered  office or transfer  agent.  If TSA  exercises its
purchase  rights,  the delivery  must be made to the transfer  agent.  In either
case,  upon  receipt  of the  certificates  and other  required  documents,  the
holders  will be  entitled  to receive  one share of TSA  common  stock for each
outstanding  TSA  Exchangeco  exchangeable  share,  plus  an  additional  amount
equivalent  to  all  declared  and  unpaid   dividends  on  the  TSA  Exchangeco
exchangeable  shares.  TSA  Exchangeco may require the holder to pick up the TSA
common stock at TSA Exchangeco's  registered office.  TSA or TSA Exchangeco,  as
the case may be, is  entitled  to sell some of the TSA  common  stock  otherwise
deliverable to the holder to fund any withholding tax obligation.

         As  an  alternative   to  the  exchange   described  in  the  preceding
paragraph,  a holder of TSA  Exchangeco  exchangeable  shares may  exercise  its
exchange  right and  require  TSA to purchase  the TSA  Exchangeco  exchangeable
shares.   In  this  case,   the  holder   must   deliver  to  the   trustee  the
certificates,  endorsed in blank,  a completed form of notice of exercise of the
exchange  right,  which is  contained on the reverse of, or attached to, the TSA
Exchangeco exchangeable share certificates and any other required documents.

Liquidation Of TSA

         Upon the occurrence of a TSA  liquidation  event (as described  below),
in  order  for  the  holders  of  the  TSA  Exchangeco  exchangeable  shares  to
participate  on a pro rata basis with the  holders  of TSA  common  stock,  each
holder of TSA  Exchangeco  exchangeable  shares  will  automatically  receive in
exchange  therefor an equivalent  number of shares of TSA common stock,  plus an
additional  amount  equivalent to all declared and unpaid  dividends on such TSA
Exchangeco exchangeable shares.  A TSA liquidation event means:

                  (1)      any  determination  by TSA's  board of  directors  to
         institute   voluntary   liquidation,    dissolution,    or   winding-up
         proceedings  with  respect to TSA or to effect  any other  distribution
         of assets of TSA among its  stockholders  for the purpose of winding up
         its affairs; or

                  (2)      as soon  as  practicable  following  the  earlier  of
         receipt by TSA of notice of, and TSA becoming  aware of any  threatened
         or  instituted   claim,   suit  or  proceedings  with  respect  to  the
         involuntary  liquidation,  dissolution  or  winding-up  of  TSA  or  to
         effect any other  distribution of assets of TSA among its  stockholders
         for the  purpose of winding up its  affairs,  in either  case where TSA
         has failed to contest in good faith any of these  proceeding  within 30
         days of becoming aware of it.

To effect the  automatic  exchange  of TSA  Exchangeco  exchangeable  shares for
shares of TSA common stock,  TSA will purchase each TSA Exchangeco  exchangeable
share  outstanding  immediately  prior  to the  TSA  liquidation  event.  Upon a
holder's   request  and   surrender  of  TSA   Exchangeco   exchangeable   share
certificates,   endorsed  in  blank  and  accompanied  by  such  instruments  of
transfer  as TSA may  reasonably  require,  TSA  will  deliver  to that  holder,
certificates  representing  an equivalent  number of shares of TSA common stock,
plus an additional  amount  equivalent  to all declared and unpaid  dividends on
the holder's TSA Exchangeco  exchangeable  shares and, to the extent not paid by
TSA  Exchangeco,  dividends  declared  on TSA  common  stock  that have not been
declared on the TSA Exchangeco  exchangeable  shares as required under the terms
of the TSA  Exchangeco  exchangeable  shares.  TSA is  entitled  to sell some of
the  TSA  common  stock  otherwise   deliverable  to  the  holder  to  fund  any
withholding tax obligation.

         Subject  to  limitations  with  respect  TSA  Exchangeco   exchangeable
shares held in Canadian  Registered  Retirement  Savings  Plans,  TSA may assign
the retraction  call right,  redemption  call right and  liquidation  call right
described above to Transaction  Systems  Architects  Nova Scotia Company,  which
we refer to as TSA Holdco.  TSA Holdco is a wholly-owned subsidiary of TSA.

                            INCOME TAX CONSIDERATIONS

Canadian   Federal   Income  Tax   Considerations   To  Former   MessagingDirect
Shareholders

         Subject to the  qualifications  and assumptions  contained  herein,  in
the opinion of Baker & McKenzie,  Canadian tax counsel to TSA, the  following is
a summary of the principal  Canadian  federal income tax  considerations,  as of
the date of this  prospectus  generally  applicable  to  former  MessagingDirect
shareholders  who at all relevant  times,  for purposes of the Canadian Tax Act,
hold their TSA  Exchangeco  exchangeable  shares and shares of TSA common  stock
as  capital  property  and deal at arm's  length  with,  and are not  affiliated
with,  MessagingDirect  or TSA. This  discussion does not apply to a holder with
respect to whom TSA is a foreign  affiliate  within the meaning of the  Canadian
Tax  Act.  It  is  assumed  that  a  former   MessagingDirect   shareholder  who
exchanged  MessagingDirect common shares for TSA Exchangeco  exchangeable shares
received no other  consideration for the MessagingDirect  common shares,  except
for cash in lieu of a  fraction  of a TSA  Exchangeco  exchangeable  share.  The
rights  described  below under the heading  Voting  Rights and  Exchange  Rights
will  be  received  by  former   MessagingDirect   shareholders   from  TSA.  No
assurance  can be given that these  rights  will not be  regarded  as  non-share
consideration received for the MessagingDirect common shares.

         All former  MessagingDirect  shareholders  should consult their own tax
advisors  as to  whether,  as a matter of fact,  they hold their TSA  Exchangeco
exchangeable  shares and shares of TSA common stock as capital  property for the
purposes of the  Canadian Tax Act.  The  "mark-to-market"  rules of the Canadian
Tax Act relating to financial  institutions  (including financial  institutions,
registered  securities  dealers and  corporations  controlled  by one or more of
the foregoing)  will preclude those financial  institutions  from treating their
TSA  Exchangeco  exchangeable  shares and shares of TSA common  stock as capital
property for purposes of the Canadian  Tax Act.  This  discussion  does not take
into account the mark-to-market rules, and former  MessagingDirect  shareholders
that are financial  institutions  for the purposes of these rules should consult
their  own  tax  advisors  to  determine  the  tax  consequences  to them of the
combination.

         This  discussion  is based on the current  provisions  of the  Canadian
Tax  Act  and  the  regulations  thereunder,   the  current  provisions  of  the
Canada-United States Income Tax Convention,  and counsel's  understanding of the
current  published  administrative  practices of  the Canada Customs and Revenue
Agency, all of which are subject to change.  This discussion  takes into account
all specific  proposals  to  amend  the  Canadian  Tax  Act and the  regulations
thereunder  that have  been  publicly  announced by or on behalf of the Canadian
Minister of Finance before the date hereof.  No assurances can be given that the
proposed amendments  will be enacted in the form proposed, if at all.

         Except for the foregoing,  this  discussion  does not take into account
or anticipate  any changes in law,  whether by  legislative,  administrative  or
judicial  decision  or  action,  nor  does  it  take  into  account  provincial,
territorial  or  foreign  income tax  legislation  or  considerations  which may
differ from the Canadian federal income tax considerations described herein.

         This  discussion  is  of  a  general  nature  only.  Therefore,  former
MessagingDirect   shareholders  should  consult  their  own  tax  advisors  with
respect to their  particular  circumstances.  No  advance  income tax ruling has
been  obtained  from the Canada  Customs and Revenue Agency  to confirm  the tax
consequences of any of the transactions described herein.

         Conversion  from U.S.  Dollars to  Canadian  Dollars.  For  purposes of
the  Canadian  Tax Act,  all  amounts  relating to the  acquisition,  holding or
disposition of shares of TSA common stock,  including  dividends,  adjusted cost
base and  proceeds of  disposition,  must be  converted  into  Canadian  dollars
based on the  prevailing  United  States  dollar  exchange rate at the time such
amounts  arise.  In  computing  a  shareholder's  liability  for tax  under  the
Canadian Tax Act, any cash amounts  received by a  shareholder  in United States
dollars must be converted into the Canadian  dollar  equivalent,  and the amount
of any non-share  consideration  received by a shareholder  must be expressed in
Canadian dollars at the time the consideration is received.

Shareholders Resident in Canada

         The following  portion of this  discussion  is generally  applicable to
holders of TSA  Exchangeco  exchangeable  shares  who,  for the  purposes of the
Canadian  Tax Act and any  applicable  income  tax  treaty  or  convention,  are
resident or deemed to be resident in Canada at all  relevant  times.  Certain of
these  persons  to whom the  former  MessagingDirect  common  shares  might  not
constitute  capital  property may elect, in certain  circumstances,  to have the
property  treated  as  capital  property  by  making  the  irrevocable  election
permitted by subsection 39(4) of the Canadian Tax Act.

         Retraction of TSA Exchangeco  Exchangeable  Shares with TSA Exchangeco;
Redemption  of TSA  Exchangeco  Exchangeable  Shares by TSA  Exchangeco.  On the
retraction or redemption of a TSA Exchangeco  exchangeable  share with or by TSA
Exchangeco,  the holder of a TSA  Exchangeco  exchangeable  share will be deemed
to have received a dividend  equal to the amount,  if any, by which the proceeds
exceed  the  paid-up  capital  at the  time of the TSA  Exchangeco  exchangeable
share  redemption.  For these  purposes,  the  proceeds  will be the fair market
value at the time of the retraction or  redemption,  of the shares of TSA common
stock received from TSA Exchangeco  plus the amount,  if any, of all accrued but
unpaid  dividends  on  the  TSA  Exchangeco  exchangeable  shares  paid  on  the
retraction or redemption.  The amount of the deemed  dividend  generally will be
subject to the same tax  treatment  accorded to dividends on the TSA  Exchangeco
exchangeable  shares as described  below.  On the retraction or redemption,  the
holder of a TSA  Exchangeco  exchangeable  share will also be considered to have
disposed  of the  TSA  Exchangeco  exchangeable  share,  but the  amount  of the
deemed  dividend  will be excluded in computing  the  shareholder's  proceeds of
disposition  for purposes of computing  any capital gain or capital loss arising
on the  disposition.  In the case of a  shareholder  that is a  corporation,  in
some  circumstances,  the amount of any such deemed  dividend  may be treated as
proceeds of disposition and not as a dividend.

         Exchange  of  TSA  Exchangeco  Exchangeable  Shares  with  TSA  or  TSA
Holdco.  Because of TSA's or TSA Holdco's  retraction  call right and redemption
call  right,  an  exchange  with  TSA or TSA  Holdco  results  in  TSA's  or TSA
Holdco's  purchase of the TSA Exchangeco  exchangeable  shares.  The holder will
generally  realize a capital  gain (or a capital  loss)  equal to the  amount by
which the proceeds of  disposition of the TSA  Exchangeco  exchangeable  shares,
net of any  reasonable  costs of  disposition,  exceed  (or are less  than)  the
adjusted  cost base to the  holder  of the TSA  Exchangeco  exchangeable  shares
immediately   before  the  exchange.   For  these  purposes,   the  proceeds  of
disposition  will be the  fair  market  value  at the  time of  exchange  of the
shares of TSA common  stock plus any other  amount  received  by the holder from
TSA or TSA Holdco as part of the exchange consideration.

         In the  Canadian  federal  budget of October  18,  2000,  the  Canadian
government  announced  its intention to develop a rollover rule which will allow
a Canadian  resident  shareholder to exchange  shares of a Canadian  corporation
for shares of a  non-Canadian  corporation  on a  tax-deferred  basis  where the
Canadian  resident   shareholder   receives  only  share  consideration  on  the
exchange.  Any  rollover  rule will not take effect  before the release of draft
legislation  for  public  discussion.  No  assurance  can  be  given  that  this
proposed rollover rule will ever be enacted.  This analysis assumes that no such
rollover  rule  will  be  available  to  holders of  TSA Exchangeco exchangeable
shares.

         Because  of the  existence  of TSA's or TSA  Holdco's  retraction  call
right,  a  holder   exercising  the  right  of  retraction  in  respect  of  TSA
Exchangeco  exchangeable  shares cannot control  whether the holder will receive
shares  of TSA  common  stock  by  way  of  redemption  of  the  TSA  Exchangeco
exchangeable  shares  by TSA  Exchangeco  or by the way of  purchase  of the TSA
Exchangeco  exchangeable  shares by TSA or TSA Holdco.  As described  above, the
Canadian  federal income tax  consequences of a redemption  differ from those of
a purchase.

         Taxation of Capital  Gains and Capital  Losses.  Three-quarters  of any
capital  gain  ("taxable  capital  gain") must be  included  in a  shareholder's
income  for  the  year  of  disposition.  Three-quarters  of  any  capital  loss
("allowable  capital  loss")  generally  must be  deducted  by the  holder  from
taxable  capital  gains  for the  year of  disposition.  Any  allowable  capital
losses  in  excess  of  taxable  capital  gains  for  the  year  of  disposition
generally  may be carried  back up to three  taxation  years or carried  forward
indefinitely  and deducted  against net taxable  capital gains (taxable  capital
gains less  allowable  capital  losses) in those  other  years to the extent and
under  the  circumstances  described  in the  Canadian  Tax  Act.  The  Canadian
federal  budgets of February  28,  2000 and  October 18, 2000  propose to reduce
the inclusion  rates for capital  gains from  three-quarters  to two-thirds  and
one-half  in respect of capital  gains  realized  after  February  27,  2000 and
October 17, 2000,  respectively.  Where a taxpayer  has capital  gains or losses
in more than one of three  periods in 2000  (January 1 to February 27,  February
28 to October 17, and October 18 to December 31), the effective  inclusion  rate
for the 2000 year is determined in accordance  with a formula.  No assurance can
be given that this proposal will be enacted.

         Capital  gains  realized by an  individual  or trust,  other than other
certain  specified  trusts,  may give rise to alternative  minimum tax under the
Canadian Tax Act.

         A  shareholder  that  is  throughout  the  relevant   taxation  year  a
"Canadian-controlled  private  corporation" (as defined in the Canadian Tax Act)
may be liable to pay an additional  refundable  tax of 6 2/3% on its  "aggregate
investment  income"  for the year  which  will  include  an amount in respect to
taxable capital gains.

         If  the   holder  of  a  TSA   Exchangeco   exchangeable   share  is  a
corporation,  the amount of any  capital  loss  arising  from a  disposition  or
deemed  disposition  of the  share may be  reduced  by the  amount of  dividends
received  or deemed to have been  received  by it on the share to the extent and
under  circumstances  prescribed  by the  Canadian  Tax Act.  Similar  rules may
apply where a  corporation  is a member of a partnership  or a beneficiary  of a
trust  that  owns  TSA  Exchangeco  exchangeable  shares  or  where a  trust  or
partnership  of which a corporation  is a beneficiary or a member is a member of
a  partnership   or  a  beneficiary   of  a  trust  that  owns  TSA   Exchangeco
exchangeable  shares.  Shareholders  to whom these rules may be relevant  should
consult their own tax advisors.

         Dividends  on TSA  Exchangeco  Exchangeable  Shares.  In the  case of a
shareholder  who is an individual,  dividends  received or deemed to be received
on the TSA  Exchangeco  exchangeable  shares will be included in  computing  the
shareholder's  income,  and will be subject to the  gross-up  and  dividend  tax
credit rules  normally  applicable  to taxable  dividends  received from taxable
Canadian corporations.

         In the  case  of a  shareholder  that  is a  corporation  other  than a
"specified  financial  institution"  (as  defined  in  the  Canadian  Tax  Act),
dividends  received or deemed to be received on the TSA Exchangeco  exchangeable
shares normally will be included in the  corporation's  income and deductible in
computing its taxable income.

         A  shareholder  that is a  "private  corporation"  (as  defined  in the
Canadian  Tax Act) or any other  corporation  resident in Canada and  controlled
or deemed to be  controlled  by or for the benefit of an individual or a related
group of  individuals  may be liable  under Part IV of the  Canadian  Tax Act to
pay a refundable  tax of 33 1/3% of dividends  received or deemed to be received
on the TSA Exchangeco  exchangeable  shares to the extent that the dividends are
deductible in computing the shareholder's taxable income.

         The  TSA  Exchangeco   exchangeable  shares  will  be  "term  preferred
shares" as  defined  in the  Canadian  Tax Act.  Consequently,  in the case of a
shareholder that is a specified financial  institution,  such a dividend will be
deductible in computing its taxable income only if:

                  (1)      the specified  financial  institution did not acquire
         the TSA Exchangeco  exchangeable  shares in the ordinary  course of the
         business carried on by the institution; or

                  (2)      in any case,  at the time the  dividend  is  received
         by  the   specified   financial   institution,   the   TSA   Exchangeco
         exchangeable  shares  are  listed on a  prescribed  stock  exchange  in
         Canada  and  the  specified  financial  institution,  either  alone  or
         together  with  persons  with  whom it does not  deal at arm's  length,
         does not  receive (or is not deemed to  receive)  dividends  in respect
         of  more  than  10%  of  the  issued  and  outstanding  TSA  Exchangeco
         exchangeable shares.  However,  the TSA Exchangeco  exchangeable shares
         are not  listed  on any stock  exchange  and there are no plans to list
         the TSA Exchangeco exchangeable shares on any stock exchange.

         In  addition,  to the  extent  that a  deemed  dividend  arises  on the
redemption  of the TSA  Exchangeco  exchangeable  shares  by TSA  Exchangeco,  a
portion of the dividend  may not be subject to the denial of dividend  deduction
applicable  in  respect  of  term  preferred   shares  in  accordance  with  the
exceptions  outlined  above.  Specified  financial  institutions  should consult
their own tax advisors.

         A  shareholder  that  is  throughout  the  relevant   taxation  year  a
"Canadian-controlled  private  corporation" (as defined in the Canadian Tax Act)
may be liable to pay an additional  refundable  tax of 6 2/3% on its  "aggregate
investment  income"  for  the  year  which  will  include  dividends  or  deemed
dividends that are not deductible in computing taxable income.

         The TSA  Exchangeco  exchangeable  shares  will be  "taxable  preferred
shares"  and  "short-term  preferred  shares" for  purpose of the  Canadian  Tax
Act.  Accordingly,  TSA  Exchangeco  will be subject to a 66 2/3% tax under Part
VI.1 of the Canadian Tax Act on dividends  (other than  "excluded  dividends" as
defined  in the  Canadian  Tax  Act)  paid  or  deemed  to be  paid  on the  TSA
Exchangeco  exchangeable  shares and will be entitled to deduct an amount  equal
to 9/4 of the tax so payable in  computing  its taxable  income for  purposes of
the  Canadian  Tax Act.  Dividends  received or deemed to be received on the TSA
Exchangeco  exchangeable  shares  will not be  subject to the 10% tax under Part
IV.1 of the Canadian Tax Act applicable to certain corporations.

         Dividends  on TSA  Common  Stock.  Dividends  on shares  of TSA  common
stock  will be  included  in the  recipient's  income  for the  purposes  of the
Canadian Tax Act. These  dividends  received by an individual  shareholder  will
not be subject to the  gross-up  and  dividend  tax credit rules in the Canadian
Tax Act. A  shareholder  that is a corporation  will include these  dividends in
computing  its income and  generally  will not be  entitled to deduct the amount
of the  dividends  in  computing  its  taxable  income.  A  shareholder  that is
throughout   the  relevant   taxation   year  a   "Canadian-controlled   private
corporation"  (as  defined  in the  Canadian  Tax Act) may be  liable  to pay an
additional  refundable  tax of 6 2/3% on its "aggregate  investment  income" for
the  year  which  will  include  the  dividends.   United  States   non-resident
withholding  tax on the  dividends  will be  eligible  for foreign tax credit or
deduction  treatment,  where  applicable,   under  the  Canadian  Tax  Act.  See
"United  States  Federal  Income Tax  Considerations  to Former  MessagingDirect
Shareholders  --  Shareholders  Not  Resident  in  or  Citizens  of  the  United
States."  The  Canadian  federal  budget of  October  18,  2000  proposes  a tax
deferral  on an  elective  basis in  respect of  certain  distributions  by U.S.
corporations  of  "spin-off"  shares  to  Canadian  resident  shareholders.   No
assurance can be given that this proposal will be enacted.

         Disposition  of  Shares  of TSA  Common  Stock.  The cost of a share of
TSA common  stock  received  on a  retraction,  redemption  or exchange of a TSA
Exchangeco  exchangeable  share  will be equal to the fair  market  value of the
share at the time of that event.  The  adjusted  cost base to a holder of shares
of TSA common stock  acquired on a  retraction,  redemption or exchange of a TSA
Exchangeco  exchangeable  share will be  determined by averaging the cost of the
share with the  adjusted  cost base of all other shares of TSA common stock held
by  the  holder  as  capital   property   immediately   before  the  retraction,
redemption  or  exchange,   as  the  case  may  be.  A  disposition   or  deemed
disposition  of a share of TSA common  stock by a holder will  generally  result
in a  capital  gain (or a  capital  loss)  equal  to the  amount  by  which  the
proceeds of  disposition,  net of any reasonable  costs of  disposition,  exceed
(or  are  less  than)  the  adjusted  cost  base  to the  holder  of  the  share
immediately before the disposition.

         Foreign  Property  Information  Reporting.  A holder  of  shares of TSA
common  stock,  who is a  "specified  Canadian  entity"  for a taxation  year or
fiscal  period and whose  total cost  amount of  "specified  foreign  property,"
including  such  shares,  at any  time in the  year  or  fiscal  period  exceeds
Cdn$100,000  will be  required  to file an  information  return  for the year or
period  disclosing  prescribed  information,  including the  shareholder's  cost
amount,  any dividends  received in the year,  and any gains or losses  realized
in  the  year, in  respect  of  that  property.  Trusts  governed  by registered
retirement  savings plans, registered  retirement income  funds, deferred profit
sharing  plans  and  registered  pension plans  will not  be specified  Canadian
entities.  With some exceptions, other taxpayers resident in Canada  in the year
will be specified Canadian entities. A holder of TSA common stock should consult
its own advisors about whether it must comply with these rules.

         TSA  Exchangeco  Exchangeable Shares - Eligibility for Investment.  The
TSA Exchangeco  exchangeable shares will be  foreign property under the Canadian
Tax Act for trusts governed by registered retirement savings  plans,  registered
retirement  income funds and  deferred  profit  sharing  plans,  for  registered
pension  plans or for certain  other persons to whom Part XI of the Canadian Tax
Act  applies.  These  plans,  funds and  tax-exempt  persons have to limit their
investment in TSA  Exchangeco  exchangeable  shares and TSA common stock or risk
incurring  penalties  under  the  Canadian  Tax  Act.  The  Canada  Customs  and
Revenue  Agency  has  stated  that the  penalties  will not be levied  where the
shares  are  not  qualified   investments   for  trusts   governed  by  Canadian
retirement  savings  plans,  registered  retirement  income  funds and  deferred
profit  sharing  plans and  subject  to the  taxes  described  in the  following
paragraph.

         The  TSA   Exchangeco   exchangeable   shares  will  not  be  qualified
investments  under  the  Canadian  Tax Act for  trusts  governed  by  registered
retirement  savings  plans,  registered  retirement  income  funds and  deferred
profit sharing plans.  The  acquisition  of TSA Exchangeco  exchangeable  shares
by these plans and funds will  result in an income  inclusion  to the  annuitant
under  these  plans  and  funds  equal  to the  fair  market  value  of the  TSA
Exchangeco  exchangeable  shares,  and these  plans and funds will also be taxed
on the income and gains from the TSA  Exchangeco  exchangeable  shares under the
Canadian Tax Act.

         Voting  Rights and  Exchange  Rights.  The rights of the holders of TSA
Exchangeco  exchangeable  shares  to  direct  the  voting  of the one  share  of
MessagingDirect  special  preferred  voting  stock  held  by a  trustee  and the
rights  granted to the trustee to exchange TSA  Exchangeco  exchangeable  shares
for  TSA  common   stock  in  certain   circumstances   will  not  be  qualified
investments and will be foreign property under the Canadian Tax Act.

         TSA  Common   Stock.   The  TSA  common   stock  will  be  a  qualified
investment  under  the  Canadian  Tax  Act for  trusts  governed  by  registered
retirement  savings  plans,  registered  retirement  income  funds and  deferred
profit  sharing  plans  provided  that the  shares  remain  listed on the Nasdaq
National  Market or a prescribed  stock  exchange.  The TSA common stock will be
foreign property under the Canadian Tax Act.

Shareholders Not Resident in Canada

         The  following  portion  of  the  discussion is  applicable  to  former
MessagingDirect shareholders who, for  purposes of  the Canadian Tax Act and any
applicable  tax treaty or convention, have  not been and will not be resident or
deemed to be resident in Canada at any time.

         Generally,   the  TSA  Exchangeco  exchangeable shares will be  taxable
Canadian  property  to  a  non-resident  of  Canada  since TSA  Exchangeco  is a
corporation  resident in  Canada and  the TSA Exchangeco exchangeable shares are
not listed on a prescribed  stock  exchange.  It is not anticipated that the TSA
Exchangeco  exchangeable  shares will ever be listed on any stock exchange.

         A  non-resident  of  Canada  is  subject  to  tax on  any  gain  on the
exchange of TSA  Exchangeco  exchangeable  shares for shares of TSA common stock
(except to the extent the  exchange  gives rise to a deemed  dividend  discussed
below),  or on the sale or other  disposition of a TSA  Exchangeco  exchangeable
share.  Canada's  tax  treaties  will  generally  exempt  any  gain  from tax in
Canada.  However,  a holder who is a non-resident  will generally be required to
obtain a clearance  certificate  under  Section 116 of the  Canadian  Tax Act in
respect  of a  disposition  of  taxable  Canadian  property  even where a treaty
exemption  applies,  failing  which TSA  Exchangeco,  TSA or TSA Holdco,  as the
case may be, will be entitled  to withhold a portion of the  proceeds  under the
Canadian Tax Act.

         Dividends   paid  or   deemed   to  be  paid  on  the  TSA   Exchangeco
exchangeable  shares  are  subject  to  non-resident  withholding  tax under the
Canadian  Tax Act at the rate of 25%,  although  this rate may be reduced  under
the provisions of an applicable  income tax treaty or  convention.  For example,
under the  Canada-United  States  Income Tax  Convention,  the rate is generally
reduced to 15% in respect of  dividends  paid to a person who is the  beneficial
owner  thereof  and who is  resident  in the United  States for  purposes of the
Canada-United States Income Tax Convention.

         A holder whose TSA Exchangeco  exchangeable  shares are redeemed by TSA
Exchangeco  (either under TSA  Exchangeco's  redemption right or pursuant to the
holder's  retraction  rights)  will be deemed to receive a dividend as described
above  under  "--   Shareholders   Resident  in  Canada  --  Retraction  of  TSA
Exchangeco   Exchangeable   Shares  with  TSA  Exchangeco;   Redemption  of  TSA
Exchangeco  Exchangeable  Shares by TSA  Exchangeco."  Any such deemed  dividend
will  be  subject  to  withholding  tax  as  described  above.  Holders  of  TSA
Exchangeco  exchangeable  shares  cannot  control  whether  they will  realize a
deemed   dividend  or  proceeds  of  disposition  on  an  exchange  of  the  TSA
Exchangeco exchangeable shares for shares of TSA common stock.

        The TSA common  stock will  not be  taxable Canadian  property to a non-
resident of Canada since TSA is not a corporation resident in Canada. Therefore,
any gain on the sale of TSA common stock by a non-resident of Canada will not be
taxable in Canada.

United  States  Federal  Income  Tax  Considerations  -  Former  MessagingDirect
Shareholders Not Resident In, Or Citizens Of, The United States

         The  following  summary  applies to former  holders of  MessagingDirect
common  shares  that  are  not  United  States  holders.  For  purposes  of this
summary,  United  States  holders  are  individual  United  States  citizens  or
residents  (including  certain former citizens and  residents),  corporations or
partnerships  organized  in the  United  States or under the laws of the  United
States or any state  thereof,  any  estate  subject  to  United  States  federal
income  tax on its  income  regardless  of  source,  and any  trust  if a United
States court is able to exercise  primary  supervision  over the  administration
of the trust and one or more United  States  persons  have  authority to control
all substantial decisions of the trust.

         Under the Plan of  Arrangement,  United States holders are not entitled
to receive TSA  Exchangeco  exchangeable  shares,  and holders of TSA Exchangeco
exchangeable  shares are prohibited from transferring their exchangeable  shares
except to surrender them to TSA.

         This  summary  is based on  United  States  Federal  income  tax law in
effect  on  the  date  of  this   prospectus.   No   statutory,   judicial,   or
administrative  authority  directly  addresses some of the United States Federal
income tax  consequences  of the  issuance  and  ownership  of  instruments  and
rights  comparable  to the TSA  Exchangeco  exchangeable  shares and the related
rights.  Consequently,  some  aspects of the United  States  federal  income tax
treatment  of the  transactions,  including  the  ownership  of  TSA  Exchangeco
exchangeable  shares and the exchange of TSA Exchangeco  exchangeable shares for
shares of TSA common stock,  are not certain.  No advance  income tax ruling has
been  sought  or  obtained  from the  United  States  Internal  Revenue  Service
regarding the tax consequences of any of the transactions described herein.

         This summary does not address  aspects of United States  taxation other
than  United  States  Federal  income  taxation.  We note as a  general  matter,
however,  that  United  States  income  tax  treaties  do not apply to state and
local taxes.  In addition,  this summary does not address  either (1) the United
States state or local tax  consequences  or (2) the foreign tax  consequences of
the combination of MessagingDirect, TSA Exchangeco and TSA.

         A non-United States  holder  generally  should not be subject to United
State  federal income  tax on  gain (if any) recognized  on the  exchange of TSA
Exchangeco  exchangeable shares  for shares of TSA  common  stock or on gain (if
any) on the sale of  shares of TSA common stock.  Either gain  could be taxable,
however, in two very limited circumstances.

         First,  the  gain  could  be  taxed  by the  United  States  if (1) the
non-United  States  holder  has an  office  or fixed  place of  business  in the
United  States;  (2)  that  office  materially  participates  in the sale of the
stock;  and (3) the  non-United  States  holder  is  either a dealer in stock or
engaged in the active conduct of a banking,  finance,  or similar  business.  If
these  conditions  are met,  the gain  could be taxed as  effectively  connected
income  provided  that certain  other  criteria are also met.  This tax might be
avoided  (depending  on whether the  non-United  States holder is a dealer or is
engaged in a banking,  finance,  or similar  business) if the non-United  States
holder is a qualified  resident of a country with which the United  States has a
bilateral  income tax treaty that changes the  application  of the normal source
of income rules in the Internal Revenue Code.

         Second,  gain recognized by an individual  could be taxed by the United
States if the  individual  is present in the United  States for 183 days or more
in the  taxable  year in which the gain is  recognized  and has a "tax home," as
defined in the United  States  Internal  Revenue  Code,  during  that year.  The
gain would be taxable only if the  non-United  States  holder has a U.S.  office
and certain other narrow  criteria are  satisfied.  This tax could be avoided if
the  individual  is a  qualified  resident  of a country  with  which the United
States has a bilateral  income tax treaty,  and the  individual is a resident of
the other country under the Residence article of the treaty.

         Non-United  States  holders might  also be subject to tax if the United
States rules  regarding  investments  in United States real  property  interests
were to  apply.  TSA has  represented,  however,  that  it is  expected  that no
corporation  relevant  to  this  determination  will  be a  United  States  real
property holding company, so these rules should not apply.

         Dividends  received by a non-United  States  holder with respect to TSA
common  stock  received  in  exchange  for TSA  Exchangeco  exchangeable  shares
generally  will be subject to United States  Federal  withholding  tax at a rate
of 30  percent.  This rate  could be reduced if  non-United  States  holder is a
qualified  resident  of a country  with which the United  States has a bilateral
income  tax   treaty.   A  qualified   resident  of  Canada   under  the  United
States-Canada  income tax treaty  should be eligible  for a reduced  treaty rate
of 15% or 5%, depending on the size of the shareholding.

                                 LEGAL MATTERS

         The  validity  of the Class A Common  Stock  offered  pursuant  to this
prospectus will be passed upon for TSA by Baker & McKenzie, Dallas, Texas.

                                    EXPERTS

         The financial  statements incorporated  by reference in this prospectus
to TSA's  Annual Report on Form 10-K  for the  fiscal year  ended  September 30,
2000, have been  audited by Arthur Andersen LLP, independent public accountants,
as indicated in their  report with respect  thereto,  and are included herein in
reliance  upon the  authority  of said  firm as experts  in giving  said report.
Reference  is made to said report on the financial statements, which includes an
explanatory paragraph with respect to  TSA changing its method of accounting for
software  license fees revenue  upon adoption of American Institute of Certified
Public  Accountants  Statement of Position  97-2, "Software Revenue Recognition"
effective October 1, 1998, as discussed in Note 1 to the financial statements.

         Future  financial  statements of TSA and  the  reports thereon of TSA's
independent  public  accountants  also will be incorporated by reference in this
prospectus   in  reliance  upon   the  authority  of  those  independent  public
accountants  as  experts  in giving  those  reports  to the extent said firm has
audited  those  financial  statements  and consented to the use of their reports
thereon.

                       -----------------------------------


                                     PART II

                     INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14.  Other Expenses of Issuance and Distribution

         The  following  table sets forth the costs and expenses  payable by the
registrant  in  connection  with the  sale of the  securities  being  registered
hereby.  All amounts are estimates except the registration fee.

Registration  fee . . . . . . . . . . . . . . . . . . . . . .      $11,985
Legal  fees and  expenses . . . . . . . . . . . . . . . . . .       15,000
Accounting  fees and expenses.  . . . . . . . . . . . . . . .       25,000
Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . .        1,015

     Total  . . . . . . . . . . . . . . . . . . . . . . . . .      $53,000


Item 15.  Indemnification of Directors and Officers

         Section 145 of the General  Corporation  Law of the State of Delaware
  permits  indemnification  by a corporation of certain  officers,  directors,
  employees  and agents.  Consistent  therewith,  Article Tenth of the Amended
  and Restated  Certificate of  Incorporation of TSA provides that TSA, to the
  fullest  extent  authorized by the General  Corporation  Law of the State of
  Delaware,  as the same exists or may  hereafter be amended (but, in the case
  of any such  amendment,  only to the extent that such amendment  permits TSA
  to provide  broader  indemnification  rights than such law  permitted TSA to
  provide prior to such amendment),  to indemnify a director or officer of TSA
  or a  person  who  is or was  serving  at the  request  of TSA as  director,
  officer,  employee  or agent of  another  corporation  or of a  partnership,
  joint venture, trust or other enterprise,  including service with respect to
  an employee  benefit plan,  who was or is made (or  threatened to be made) a
  party to a civil, criminal,  administrative or investigative  proceeding (an
  "indemnified  person").  Article Tenth also provides that expenses  incurred
  by an  indemnified  person  will  be  paid  in  advance  by  TSA;  provided,
  however,  that,  if the  General  Corporation  Law of the State of  Delaware
  requires,  an  advancement  of expenses  incurred by an  indemnified  person
  incurred in his or her  capacity as a director or officer  will be made only
  if TSA receives an undertaking by or on behalf of the indemnified  person to
  repay all amounts so advanced if it shall  ultimately be determined by final
  judicial  decision  from which there is no further right to appeal that such
  indemnified  person is not  entitled to be  indemnified  for such  expenses.
  The  Amended and  Restated  Certificate  of  Incorporation  also  authorizes
  TSA to  maintain  officer  and  director  liability  insurance,  and  such a
  policy is currently in effect.

         TSA entered into Severance  Compensation  Agreements with each of its
  executive  officers and certain other employees.  Under the Agreements,  TSA
  agrees to indemnify the employee to the fullest  extent  permitted by law if
  the  employee  is a party or  threatened  to be made a party to any  action,
  suit or  proceeding  in which the employee is involved by reason of the fact
  that the  employee  is or was a director or officer of TSA, by reason of any
  action  taken by him or of any action on his part while  acting as  director
  or  officer  of TSA,  or by reason of the fact that he is or was  serving at
  the  request of TSA as a  director,  officer,  employee  or agent of another
  enterprise.  TSA also  agrees  to  obtain  and  maintain  a  directors'  and
  officers' liability insurance policy covering the employee.

         Under a  registration rights agreement between TSA and certain of its
  stockholders, TSA  agreed to  indemnify each stockholder  selling his or her
  shares thereunder   in  connection  with  any  losses,  claims,  damages  or
  liabilities arising  out of certain  acts  or  omissions  of  TSA.  Under an
  agreement with the  purchasers of TSA's  Senior Convertible  Preferred Stock
  and  warrants,  TSA  indemnified   the  purchasers   with   respect  to  any
  misrepresentation   or   breach  of   any  representation  or  warranty   or
  noncompliance  with  any  conditions or  other  agreements  given or made in
  connection with the agreement or the transactions contemplated therein.

Item 16. Exhibits

Exhibit
Number             Description

   3.01(1)         Amended and Restated Certificate of Incorporation of TSA, and
                   amendments thereto
   3.02(2)         Amended and Restated Bylaws of TSA
   4.01(1)         Form of Common Stock Certificate
   5.01 *          Opinion of Baker & McKenzie
   8.01 *          Opinion of Baker & McKenzie regarding tax matters
   8.02 *          Opinion of Arthur Andersen LLP regarding tax matters
  23.01            Consent of Arthur Andersen LLP
  23.02 *          Consent of Baker & McKenzie (included in opinion filed as
                   Exhibit 5.01)
  23.03 *          Consent of Baker & McKenzie (included in opinion filed as
                   Exhibit 8.01)
  23.04 *          Consent of Arthur Andersen LLP (included in opinion filed as
                   Exhibit 8.02)
  24.01 *          Power of Attorney

(1)      Incorporated  by  reference  to the  exhibit of the same  number to the
         Registrant's Registration Statement No. 33-88292 on Form S-1.

(2)      Incorporated  by  reference  to the  exhibit of the same  number to the
         Registrant's  Annual  Report on Form  10-K for the  fiscal  year  ended
         September 30, 1999.

 *       Previously filed.

Item 22. Undertakings

         (a)      The undersigned registrant hereby undertakes:

         (1)      To file,  during  any  period  in which  offers  or sales  are
                  being  made, a post-effective  amendment to  this registration
                  statement:

                  (i)      To  include  any   prospectus   required  by  Section
         10(a)(3) of the Securities Act of 1933;

                  (ii)     To  reflect  in the  prospectus  any  facts or events
         arising  after the  effective  date of the  registration  statement (or
         the most recent post-effective  amendment thereof) which,  individually
         or  in  the   aggregate,   represent  a   fundamental   change  in  the
         information set forth in the  registration  statement.  Notwithstanding
         the  foregoing,  any  increase  or  decrease  in volume  of  securities
         offered (if the total  dollar  value of  securities  offered  would not
         exceed that which was  registered)  and any  deviation  from the low or
         high end of the estimated  maximum  offering  range may be reflected in
         the form of  prospectus  filed  with the  Commission  pursuant  to Rule
         424(b)  if,  in  the  aggregate,   the  changes  in  volume  and  price
         represent no more than a 20% change in the maximum  aggregate  offering
         price set forth in the  "Calculation of Registration  Fee" table in the
         effective registration statement; and

                  (iii)    To include any material  information  with respect to
         the plan of distribution  not previously  disclosed in the registration
         statement  or  any  material   change  to  such   information   in  the
         registration statement;

provided,  however,  that  paragraphs  (a)(1)(i) and  (a)(1)(ii) do not apply if
the information  required to be included in a post-effective  amendment by those
paragraphs  is  contained  in periodic  reports  filed with or  furnished to the
Commission  by the  registrant  pursuant  to section 13 or section  15(d) of the
Securities  Exchange  Act of 1934  that are  incorporated  by  reference  in the
registration statement.

         (2)      That, for the purpose of determining  any liability  under the
Securities Act of 1933,  each such  post-effective  amendment shall be deemed to
be a new  registration  statement  relating to the securities  offered  therein,
and the  offering  of such  securities  at that  time  shall be deemed to be the
initial bona fide offering thereof.

         (3)      To  remove  from  registration  by means  of a  post-effective
amendment  any of the  securities  being  registered  which remain unsold at the
termination of the offering.

         (b)      The   undersigned  registrant   hereby  undertakes  that,  for
purposes of determining  any liability  under the  Securities Act of 1933,  each
filing of the  registrant's  annual report  pursuant to Section 13(a) or Section
15(d) of the  Securities  Exchange  Act of 1934  (and,  where  applicable,  each
filing of an employee  benefit  plan's annual  report  pursuant to Section 15(d)
of the  Securities  Exchange Act of 1934) that is  incorporated  by reference in
the registration  statement shall be deemed to be a new  registration  statement
relating  to  the  securities   offered  therein,   and  the  offering  of  such
securities  at that time shall be deemed to be the  initial  bona fide  offering
thereof.

         (c)      Insofar as indemnification for liabilities  arising  under the
Securities Act may be permitted to directors,  officers and controlling  persons
of the  registrant  pursuant to the  foregoing  provisions,  or  otherwise,  the
registrant  has been advised that in the opinion of the  Securities and Exchange
Commission  such  indemnification  is against  public policy as expressed in the
Act  and  is,  therefore,   unenforceable.   In  the  event  that  a  claim  for
indemnification  against  such  liabilities  (other  than  the  payment  by  the
registrant of expenses  incurred or paid by a director,  officer or  controlling
person of the  registrant  in the  successful  defense  of any  action,  suit or
proceeding)  is  asserted by such  director,  officer or  controlling  person in
connection with the securities being  registered,  the registrant  will,  unless
in the  opinion  of its  counsel  the matter  has been  settled  by  controlling
precedent,  submit to a court of appropriate  jurisdiction  the question whether
such  indemnification  by it is against  public  policy as  expressed in the Act
and will be governed by the final adjudication of such issue.



                                   SIGNATURES
         The  Registrant.  Pursuant to the  requirements  of the  Securities Act
of 1933,  the  registrant  has duly  caused  this amendment to  the registration
statement  to be  signed  on its  behalf  by  the  undersigned,  thereunto  duly
authorized, in the City of Omaha, State of Nebraska, on this 9th day of January,
2001.

                                        TRANSACTION SYSTEMS ARCHITECTS, INC.

                                        By:/s/ Dwight G. Hanson
                                        ---------------------------------
                                               Dwight G. Hanson,
                                               Chief Financial Officer,
                                               Treasurer and Senior
                                               Vice President


         Pursuant  to the  requirements  of the  Securities  Act of  1933,  this
amendment to the registration statement has been signed by the following persons
in the capacities and on the dates indicated.


Name                        Title                                Date

            *               Chairman, Chief Executive            January 9, 2001
- -------------------------   Officer and Director
    William E. Fisher      (Principal Executive Officer)


/s/ Dwight G. Hanson        Chief Financial Officer and          January 9, 2001
- -------------------------   Senior Vice President
    Dwight G. Hanson       (Principal Financial Officer)

            *               Controller                           January 9, 2001
- -------------------------  (Principal Accounting Officer)
    Edward C. Fuxa

            *               Director                             January 9, 2001
- -------------------------
    Charles E. Noell, III

            *               Director                             January 9, 2001
- -------------------------
    Jim D. Kever

            *               Director                             January 9, 2001
- -------------------------
    Larry G. Fendley

            *               Director                             January 9, 2001
- -------------------------
    Roger K. Alexander

            *               Director                             January 9, 2001
- -------------------------
    Gregory J. Duman


/s/ Dwight G. Hanson
- -------------------------
 * Dwight G. Hanson as
   Attorney-In-Fact
   Pursuant to Power of
   Attorney Granted in
   Registration Statement
   No. 333-49804

                                  EXHIBIT INDEX

Exhibit
Number             Description

   3.01(1)         Amended and Restated Certificate of Incorporation of TSA, and
                   amendments thereto
   3.02(2)         Amended and Restated Bylaws of TSA
   4.01(1)         Form of Common Stock Certificate
   5.01 *          Opinion of Baker & McKenzie
   8.01 *          Opinion of Baker & McKenzie regarding tax matters
   8.02 *          Opinion of Arthur Andersen LLP regarding tax matters
  23.01            Consent of Arthur Andersen LLP
  23.02 *          Consent of Baker & McKenzie (included in opinion filed as
                   Exhibit 5.01)
  23.03 *          Consent of Baker & McKenzie (included in opinion filed as
                   Exhibit 8.01)
  23.04 *          Consent of Arthur Andersen LLP (included in opinion filed as
                   Exhibit 8.02)
  24.01 *          Power of Attorney


(1)      Incorporated  by  reference  to the  exhibit of the same  number to the
         Registrant's Registration Statement No. 33-88292 on Form S-1.

(2)      Incorporated  by  reference  to the  exhibit of the same  number to the
         Registrant's  Annual  Report on Form  10-K for the  fiscal  year  ended
         September 30, 1999.

 *       Previously filed.


As independent  public  accountants,  we hereby consent to the  incorporation by
reference  in this  amendment to the registration  statement of our report dated
October 26, 2000, included in  Transaction  Systems  Architects,  Inc.'s  Annual
Report on Form 10-K  for the  fiscal  year ended  September 30, 2000, and to all
references to our Firm included in this registration statement.


Omaha, Nebraska,
January 9, 2001